ComboBox Select Items - combobox

Question

I am trying to select a quantity to add to cart. For example, the drop down list of combo box consists of 1-10 and Others.. If I want to buy more than 10 products, I select the Others.. from drop down list and a text field will be appeared. This is how I set up my comboBox in javaFX:
<ComboBox fx:id="qtyComboBox" prefHeight="21.0" prefWidth="159.0" style="-fx-background-color:#D2B48C;" GridPane.columnIndex="1" GridPane.rowIndex="4">
<items>
<FXCollections fx:factory="observableArrayList">
<String fx:value="" />
<String fx:value="1" />
<String fx:value="2" />
<String fx:value="3" />
<String fx:value="4" />
<String fx:value="5" />
<String fx:value="6" />
<String fx:value="7" />
<String fx:value="8" />
<String fx:value="9" />
<String fx:value="10" />
<String fx:value="Others.." />
</FXCollections>
</items>
</ComboBox>
And this is how I get the selected item from comboBox:
if(panel.getQtyComboBox().getValue().equals("Others..")){
panel.getQtyTextField().setVisible(true);
qty = Integer.parseInt(panel.getQtyTextField().getText());
}else{
qty = Integer.parseInt(panel.getQtyComboBox().getValue());
}
However, when I choose 1-10, it can insert into database without any problem. But when I select the Others.., the text field does not appear. I wonder where did I did wrongly. Thanks in advance.